#! /usr/bin/env python
# -*- coding: utf-8 -*-

# *************************************************************
#     Filename @  bird.py
#       Author @  Huoty
#  Create date @  2014-11-01 22:52:41
#  Description @  
# *************************************************************

__metaclass__ = type  # 把所有的old-style 变成 new-style 的类

class Bird:  # or class Bird(object)
	def __init__(self):
		self.hungry = True
	def eat(self):
		if self.hungry:
			print "Aaaah..."
			self.hungry = False
		else:
			print "No, thanks!"

class SongBirdd(Bird):
	def __init__(self):
		super(SongBirdd, self).__init__()
		#  
		self.sound = "Squawk"
	def sing(self):
		print self.sound


# Script starts from here

sb = SongBirdd()
sb.eat()
sb.eat()